The present invention relates to the straightening and alignment of vehicle bodies and frames, more particularly, to an apparatus and method for rigidly supporting a unibody vehicle structure while carrying out alignment and straightening operations and other automotive repairs and services
Many forms of apparatus have been proposed for the straightening and alignment of vehicle frames and bodies. One type of such apparatus comprises a frame structure which is attached to the underside of the vehicle to the frame by individual clamping means. In most unibody vehicles, the clamps grip pinch welds which are along both sides of the vehicle body near the outer edge. After such a frame structure has been clamped to the vehicle, conventional force transmitting devices are attached on the frame structure at various attachment points so that the body can be pulled or pushed into its original shape.
The straightening and alignment of car bodies having a frame is relatively easy since the straightening structures can be attached directly to the frame which is much stronger than the remaining structure of the vehicle body. However, in unitized bodies, also referred to as unibody structures, this is not possible because there is no frame and the various attachment points on the vehicle are generally no stronger than the portion of the body that has been collapsed.
Since considerable effort and time on the part of skilled personnel has generally been required to move the damaged vehicle body onto such a frame or to position a frame structure underneath the vehicle, efforts have been made to simplify such frame structures to facilitate loading or mounting of the vehicle thereon. In one such frame structure a pair of transverse crossbars having clamping means thereon are clamped to the underside of a vehicle body, such as by attaching the clamps to the pinch welds. A second frame structure which may merely comprise a pair of longitudinal beams is then rolled under the crossbars and attached to the crossbars. Suitable force transmitting devices are then attached to the resulting frame structure for use in straightening and aligning the vehicle body. Such frame structures are generally mounted on rollers or wheels so as to impart a degree of mobility to the frame structure even with a vehicle loaded thereon.
The loading of a vehicle on such a frame structure still requires a considerable amount of time and skill on the part of the loading personnel. Difficulties are generally encountered in positioning the cross bars properly underneath the vehicle body because of damage to the vehicle. It is then necessary for the personnel to position and reposition with a high degree of accuracy the crossbars in order that the pinch welds may be precisely clamped to the cross bars. Not only does such an operation require skill, but there is a certain amount of danger involved to the loading personnel because of the necessity for accurately positioning the crossbar beneath the vehicle body before clamping can be achieved.
Once the vehicle has been mounted on such a frame structure, the vehicle remains at a fixed height above the supporting surface upon which the frame structure rests.
This height may be varied by jacking up the frame structure with the attached vehicle and positioning stands to support the frame structure. However, such an operation is not satisfactory because of the time involved and the lack of flexibility in subsequently modifying the working height of the vehicle or in positioning the vehicle to some other location in the shop. Such prior art frame structures comprise a number of individual components which are susceptible to being misplaced and therefore not readily available when desired to carry out a particular aspect of loading of the vehicle.